I think you mean they will shoot a heavier one with more KE than they will a lighter one which I agree with totally except there is a point at which that no longer becomes true. There is a point at which as you go up in weight (granted not at normal hunting weights) that the bow will become less efficient when the weight gets up high enough.

You posted a quote from Dr. Ashby claiming kinetic energy has absolutely nothing to do with penetration. You posted it! I said it was wrong and YOU jumped all over me defending it. YOU were defending the statement not Ashby. It doesn't matter where it came from that's begging the issue. I tried to reason with you and I even suggested that Ashby might have been exagerating to make a point but no you had your quote and it wasn't possible in your mind that it could be wrong. Well Ashby's published paper shows you were wrong to defend what absolutely was an exageration at least and yes idotic at worst. Without any thought process of your own you concluded I was wrong simply because I disagreed with your guru. Your idea of techical discussion seems to be quote and expert and ridicule anybody who might disagree with your expert but you offer no original thought of your own. That's sad.


If an expert makes a claim that every other expert in the field is wrong (and that's what you quote did) then he must believe that he is more knowlegeble than the rest of the scientific community.

First of all, you have no idea how much of an expert I may be in this area. Secondly you couldn't even answer the question about what his degree is in so you don't even know how qualified he is to talk about physics. What if he is a Dr. of psychology? Thirdly
if God himself said that 2 + 2 = 5 he would be wrong! You know experts do get it wrong from time to time and you would clearly be better off doing some thinking for yourself rather than simply paroting what you "think" somebody else believs.

No, I mean the lighter arrow will actually have more KE than the heavier arrow within a narrow weight range. I have found this to be around 4.5 to 5 gr/lb. If you get much heavier than this the heavy arrow wins,like you would expect, and if you go lower (which I don't do but on rare occasions for testing), the heavier arrow wins again......it's just in a narrow weight range that some bows experience a dramatic enough speed increase that a lower weight arrow can generate more KE than a heavier.

It's rare, and pretty cool. That's the only reason I mentioned it. I probably would not have mentioned it or discounted it as due to some error on my part, but when Mr. Mullany observed the same thing, I felt vindicated.

O.K. You guys have fun!!!

Yes indeed. But, in this case, I agree with Ashby. He layed out his reasoning exceptionally well, if you read it with an open mind.

The fact remains that most modern bowhunters are very much keyed into speed and KE. Of course, like I said before, they HAVE to be when using ultralight arrows. Reason?

As I've posted many times before: A guy using a 700 grain arrow at 150 fps can pretty much figure on getting a passthrough on a deer. A guy using a 350 gn arrow at 300 fps would also tend to expect a passthrough. If KE was the end all/be all, then this would be flat impossible. The 700 grainer is only carrying a hair under 35 ft lbs of KE while the 350 gn arrow is cranking up 70 ft lbs. With such a wide variation in KE, we have to look elsewhere to see why both arrows are capable of achieving a passthrough. We find that the common denominator is both arrows have exactly the same momentum.

The light arrow is generating it's momentum with speed. Twice the speed, twice the KE, simply to equal the momentum and penetration potential of the heavy arrow.

Hey Arthur,I can't believe you are still arguing this same old argument.I swore I was going to stay out of this ,this time.


The example you just showed leave out one of MANY variables.You know I believe that speed fights friction so that may help to explain some of the penetration power of the light arrow.


I agree that ke helps with penetration but momentum is the driving force.Ke will help the arrow maintain a straight path by the amount of naturall energy the arrow has to stay parralel to it's original path, and momentum will drive the arrow through while speed will help with fighting off friction.Bone hits without a doubt need more bone crushing power to penetrate so naturally a heavy arrow will be better but we do not always hit bone.Sometimes it is just a matter of friction and light fast arrows MAY actually be better in those instances.


We must remember that an arrow that is penetrating something is more like a machine trying to do a job.It is not a math problem.Yes theories can be proven or disproven with math problems but it is next to impossible to add ALL VARIABLES into the equation.

Those math problems don't take into account arrow compositon(material),wall thickness(aluminum),foc,TUNE,wind,fletching.etc,et c,etc.My ACC's maintain more of it's original ke and momentum downrange than aluminum.When they hit something,they flex less and drive forward so naturally they require less weight to do the same job.

I know for a fact that an arrow weighing over 700 grains with 5% foc can't penetrate as well as a 350 grain arrow with 11% foc,out of the same bow with a good tune on both.I know because I have tested it on board and foam.The heavy stopped dead and the light arrow drove through.Balance and tune,to me are more important than just a number.


Cougar has found a tried and true method for penetration.Get a PROPER SPINED arrow,balance it out and make sure the aluminum is of a thick walled variety and penetration will be awesome.The most important thing he is doing is shooting arrows that are matched to his setup and balanced right.


I do the same as far as spine and balance but I choose an ACC that is lighter but works just as well.I just laugh everytime I have to pull my arrows out of the ground that are buried deep after passing through an animal,WHILE shooting mechanicals that all the experts say are too light and the heads require too much energy to open.That out of a 58# setup @ 28 1/2" draw.A whopping 52.7 ft/lb's of ke energy.(give or take)And then remeber back to using heavy 2413's that weigh a BUNCH more with fixed heads yielding poor penetartion for me in the field.


This argument will never be settled,when physics seems to be on the side of heavy arrows but many are experiencing something a bit different in the field.Now,I think I will back out of this one for the time being.

Scoff if you like, but you only make yourself look like more of a pompous, obtuse, know-it-all than you already have previously, by discounting something so easily proveable, and observed by an engineer who has forgotten more about archery than you'll ever know.

Sylvan:

It's a shame that intelligence is challenged in the way I've seen here. Comparing vectors that shouldn't be compared is what I deem to have started such a turmoil.

I want to personally thank you for some valuable input.

Don't give me credit for anything, I switched from using 2216s to 2213's for 3D shooting several years ago specifically to gain speed on the course. I made the mistake of using them for hunting, and although I killed my share of deer with them, I noticed a loss of penetration on non-passthroughs and this was using the same broadhead. Only reason I don't or haven't gone back to aluminums is I've been shooting carbons for 4 seasons and although I believe the smaller diameter carbon arrows do improve penetration, I also believe in the heavier carbons for hunting. I am also stubborn.[8D] Thats why I am currently considering the Beman Max-4 camo arrows.....small diameter, heavier weight and advertised straightness of .003. I wish they used a uni-bushing with the ACC nocks AND I wish someone here would do a spine degradtion test on them.

LOL! I keep arguing it because so many people insist on misunderstanding it.

The point is, one CAN achieve great penetration with ultralight arrows (wich I define as 6 grains or less per pound of draw weight)... IF they have the capability of driving them fast enough. Also, as you so aptly point out about the variables, IF they are very good at tuning their bow with those fast arrows. IF they are good enough shots to place those fast - and often rather unforgiving - arrows in the correct spot. But to get momentum equal to that 700 gn/150 fps arrow, they're generating more KE than old time bowhunters were using to kill elephants in the 50's and 60's. Back then, a 45 pound recurve was the most widely favored deer hunting bow, which might have been giving a whopping 25 ft lbs of energy with wood, fiberglass or aluminum arrows.

For someone shooting low poundage, low performance bows, like those ol' 45 pound 'curves, they can still achieve excellent penetration without gobs of KE simply by increasing their momentum. The light arrow guys increase their momentum with high draw weight/high performance bows to zip those arrows along. The guys with the low performance rigs need simply increase their arrow weight.

That deal about carbons flexing less when they hit, that bugs the snot out of me. First off, I definitely agree you don't want your arrows flexing at all because they're wasting power by flexing. However, considering the average deer's chest cavity is less than 20" across, even an arrow going 150 fps is going to be through the deer in only 1/100th of a second. It won't have time to do any significant flexing anyway! Even if it did, have you ever considered that sometimes it might be a good thing to have an arrow with some flex to it? Like if it hits the edge of heavy bone, it can flex and slide around the bone rather than use up much more of it's power trying to punch through it.

Hey, as far as you talking carbon arrows vs heavy arrows - like carbon can't be heavy - you wanna try one of my GoldTips that I've got weighted up (stuffed with aquarium tubing and weedeater line) to around 750 grains? I bet they'd make your target holler hidey-ho!